FIG. 14 shows a conventional storage element 1401 that includes a bottom electrode 1403, a metal oxide layer (or chalcogenide layer) 1405, and an active layer 1407. A layer 1405 can be a solid electrolyte layer. In response to electric fields, conductive regions can be created and dissolved within the layer 1405 with metal ions provided from active layer 1407 (or an ion buffer layer). A layer 1405 can be a very thin layer, as compared to a thickness of a bottom electrode 1403.
Bottom electrode 1403 is formed in a first insulating layer 1413, and is in contact with a first interconnect (I/C) pattern 1409 formed in a second insulating layer 1415. First I/C pattern 1409 is in contact with a second I/C pattern 1411 formed in a third insulating layer 1417.
Referring still to FIG. 14, a conventional storage element 1401 can have a corner structure 1419. As shown, a bottom electrode 1403 can have an edge 1421 even after planarization steps have been performed. While such an edge 1421 is relatively small as compared to a thickness of the first electrode and interconnect layers, the edge 1421 can result in a thinning of the layer 1405. This shown by a thickness t2 being smaller than thickness t1.
A thinning of layer 1405 at edge 1421 can introduce undesirable variations in the performance of the conventional storage element 1401.